Certain problems will be addressed relating to the rapid development of physical dependence on alcohol in neural systems concerned with emotional expression. Behavioral and electrophysiological measures of withdrawal hyperexcitability will be used to trace the time course of early physical dependence following varied blood alcohol levels and durations of exposure to alcohol. Our efforts will focus on changes in excitability in the ventromedial hypothalamus and in three functionally similar but (possibly) pharmacologically distinct pathways which converge in the VM area; on changes in convergent pathways in the trigeminal motor nucleus; and on changes in conduction properties in axons of the cingulum bundle. Methods employed will include brain stimulation and electrophysiological recording (evoked potentials and unit discharges) in alert, unanesthetized preparations receiving intrajugular infusions of alcohol. Our subjects will include will include cats, Cebus monkeys and baboons. It is anticipated that the research will provide a description of the magnitude and temporal characteristics of withdrawal hyperexcitability in segments of the brain important to emotional behavior and that this information could provide useful leads toward an ultimate neurochemical understanding of the early phases of physical dependence on alcohol.